Packagings of plaster allowing a fast-opening are commercially available.
Such packagings comprise a wrapper or an envelope enfolding the plaster and they are suitable for allowing the envelope fast-opening by simply pulling the envelope ends. In particular, in such kind of packagings, the ends pulling action causes the separation of the wrapper into two semi-wrappers, one of which separates from the plaster dragging with it one protective film placed onto a part of the plaster adhesive support, which thus remains mostly uncovered and ready for application; the other semi-wrapper, together with the part of covered adhesive support, is held by the user in his/her hand, so that he/she can pull it away and reveal the whole plaster in immediate sequence.
Packagings of such a kind are disclosed, for instance in U.S. Pat. No. 4,418,822 and U.S. Pat. No. 4,235,337 in the name of the applicant.
U.S. Pat. No. 4,418,822 discloses, for instance, a packaging of plasters wherein the protective films of the adhesive support are attached to the respective semi-wrappers with a lip folded towards outside.
U.S. Pat. No. 4,235,337 discloses protective films of the adhesive support having a direct back anchor to the respective semi-wrappers.
The technical solution disclosed in U.S. Pat. No. 4,418,822 substantially concerns non-siliconated protective films.
The technical solution disclosed in U.S. Pat. No. 4,235,337 substantially concerns siliconated or anyway provided with anti-adhering treatment protective films, in case obtainable also from support material (liner) employed for the manufacturing of the plasters adhesive support.
A problem that is particularly felt with respect to the second known solution resides in that, as it can be deduced by looking at FIG. 1 depicting a longitudinal schematic section of the packaging according to the second known solution, a considerable pulling action has to be exerted on ends E1, E2 in order to open the package, since the strength to separate the semi-wrappers joined one to the other at median lines SX (cold self-welding paper) has to be added to the strength required by one of the films P1, P2 to fold onto itself, for instance as an S or as a Z, and to start detaching an initial portion of the film from the adhesive side (adhesive), a strength that in the case of FIG. 1 is made easier thanks to the presence of a bandage compress B isolating a large part of the initial portion of films P1, P2 from the adhesive.
Moreover, the applicant has noticed that, due to the required strength, it can happen, for instance, that the films initial portions, instead of folding onto themselves, tend to bend or to deviate from the desired folding so that the user is induced to exert an even greater pulling strength, that can result in a wrong opening of the packaging.